24 Volt System or 12 Volt System?

[DrivingMissLazy]

Richard, back in the late 60's and early 70's we did the same thing with the VW's. The problem we had was that the ignition coils would fry. even if we used a 12V coil with a condenser, we could plan on a replacement at least once every few days.

I do not remember having any coil problems. Can't remember if we used a resistor in the circuit or not, but I suspect we did.

Richard

[jjrbus]

Actually all the 24V lighting will work on 12 volts!!!!!  It will just be real dim.  So I dont get flamed I will mention that this is not practical for running, stop, turn lights etc.
 The Xantrex true sine wave inverters are nice, but you can use less expensive inverters like the Xantrex DR 3624 for 24 volt systems.

[Tom Y]

Chris,  I did.  I put in an 12v electronic motor and figured it would be best for me. The big down side I see is the inverter 24v is closer to 120. At the time I did not plan on putting one in but after the talk here I changed my mine. Thats the problem working years on these things ideas change. I now know what wire is on every terminal. Beware I am NOT an engineer, I just play one in my garage.  Tom Y

[cpschevy]

Ok everyone, I guess the overall answer is leave the old system and save alot of work. I  really did not realize that there was so much 24 volt stuff available for inside the house part of the bus. I will research the appliances and all the other parts i need for inside. Also thanks everyone for your input,can you all give me your brand and model of your inverters because i will probably run a basement a/c /heatpump for over the road.
                             Thanks again  for all your help    Chris

[H3Jim]

I have lots of 24 volt lights (MR16, florescents from the bus, bus lighting for the bays, other lighting left over from the bus), my refrigerator is 24 volt, my water pump is 24 volt.  I have an equalizer that I just use as a voltage splitter, so I have lots of 12 volt available for fanastic fans, some 12 volt lights, latching relays to switch all my lights, proposed ceiling fan.

I am trying to use all dc lighting, so I can have lights without turning the inverter on, particularly overnight.  The small loss from an idling inverter really adds up over a lot of hours.

[Sean]

... I  really did not realize that there was so much 24 volt stuff available for inside the house part of the bus. I will research the appliances and all the other parts i need for inside.

Chris,

Just to save you some time and frustration:  you will not find any "24-volt light fixtures."

For incandescent lighting, basically, a fixture is a fixture -- you buy 12-volt fixtures, and, if they have bulbs in them already, you toss the bulbs and replace them with 24-volt models.  Almost every style of 12-volt incandescent bulb also comes in 24-volt, however there is usually a price premium.  Finding the bulbs takes a bit of research, but they are widely available on the internet (shop around, prices vary considerably).  Like Jim, we have quite a few of the projector-lamp style (MR-10 or MR-16) fixtures, which we have on low voltage tracks.  We run all of it at 24 volts.

If you prefer LED lighting, you again buy those in 12 volt models, but buy them in pairs, and wire each pair in series.  Just make sure that you wire together only pairs of identical lights.

Fluorescent is another story.  Here you will need to find fixtures with 24-volt ballasts, or use 120-volt models (much cheaper anyway) and run them from your inverter, or run 12 volt models on 12 volts from the battery center tap, with an equalizer.

For water pumps, FloJet and Jabsco both sell a more or less identical 4.5 GPM variable-speed pump that works on 24 volts (or 12, it's a multi-voltage item).

Most of the low voltage marine refrigerators now use the Danfoss compressor system which is also dual voltage and works on either 12 or 24.

FanTastic fans, LP alarms, and the control boards of RV-style appliances like LP water heaters and absorption refrigerators are all 12 volts -- you'll need to run those from the center tap.  Again, an equalizer is recommended to keep the batteries discharging/charging evenly.

To answer your question about what inverter we chose, here is a link to our construction web site, with way more detail than you ever wanted to know about our electrical system, including all the specifications, drawings, and diagrams:
http://ourodyssey.us/bus-conversion.html
(scroll down to "Odyssey's complex electrical system")

HTH,

-Sean
http://OurOdyssey.BlogSpot.com

[jjrbus]

One of many on the net with 24V bulbs. They carry two grades Brand Name and the same bulb in generic for much less money.
                             https://www.bulbdirect.com/index.php

[mikelutestanski]

hello;     
    Some thoughts on 24Vstuff and alternative ways of doing things.. 
 
      24V ballasts are available . Look up alternative energy websites and you can get catalogs of stuff. You will also find an equalizer that Can go across the 24V batteries that will allow you to charge your batteries so that you do not discharge one battery more than the other.  The 12V equalizer post on the equalizer will provide 12V power for water pumps 12V fluorescent lighting ,fantastic vents and any other item that you cannot find in 24V.. I have a 20 amp equalizer on my battery bank that is used for the above mentioned items because when I installed those items nothing else was available.. Now there are cheaper products available for 24V applications.
     Why 24V   well the short answer is more bang for your buck. using the old water hose analogy. water pressure is the equivalent of voltage.  So the more pressure the farther the stream  out the hose goes..   Amps or amperage is the electrical equivalent of water flow.   How many gallons per minute vs amps flowing in a circuit. 
    The next part is watts or power..  Power watts is amps X volts   so  24V X 10 amps is 240 watts    10 amps X 12V is 120 W oh so it will take 20 amps at 12 volts to equal what 10 amps at 24V will do..   Get the picture more volts equals less amps for equal amounts of power .    Batteries store amps so more power is available using the same space and weight. 
      Then  the other good thing about higher voltage is that you can use smaller wire if you raise the voltage..    With higher voltage you need to shield the wire better (provide better insulation) so that the voltage does not jump out and go to ground  ie short circuit..  All elecricity likes to go to ground  thats its main function in life..  WE just make it do useful stuff for us on its way to ground.  (If you get between the electricity and ground that is is a bad thing because your heart beats because of very very small pulses of electricity and It does not take much to swamp the circuit and stop your heart.   (  8 to 15 milliamps is enough to cause that condition)) .
        Witness lightning...   millions of volts     goes   to ground wherever it wants to ; not enough resistance to stop it..

   Other parts of the subject are impedance and resistance , AC vs Dc and circuit breakers ,grounding , ground faults  etc etc etc.
     Those subjects and the  longer answers takes alot more time and many books have been written on the subject.
  ANyone can learn about electricity and its many uses  by reading..   ..
         FYI    and FWIW   the info above is mostly right but can be corrected because many things have filtered through the old mans mind over the past  6 or so decades . 
       Happy bussin  mike   

[Hartley]

Don't forget that aircraft and some military items also run 24-28 volts so there's another option for lighting if you want to get fancy or go rummaging through a surplus store...or aircraft salvage place.

The other thing is that most people that strip out transit buses might still have the 24 volt electronic flourescent ballasts. They can run some pretty big or small single-pin lamps. Some are out there that are 12 volt also, You have to look at the labels..

Just a few ideas....

Dave....